This invention pertains to a catheter for delivering a drug to a specific location within a patient""s artery.
It is known in the art to provide catheters for delivering drugs directly into the walls of a patient""s artery. An example of such a catheter is described in U.S. Pat. No. 5,746,716, issued to Vigil et al. Vigil""s catheter 1 includes a set of injectors 2 for injecting medication into an artery wall 3 (FIG. 1). Injectors 2 are mounted on a balloon 4 which is inflated when it is desired to push injectors 2 into artery wall 3. Unfortunately, injectors 2 extend in a direction perpendicular to the axis of catheter 1. Thus, when catheter 1 is inserted or withdrawn from the patient""s vascular system, there is a danger that injectors 2 will drag along and injure artery wall 3.
What is needed is an improved catheter which permits delivery of a drug into the walls of an artery where the drug is believed to be most effective.
What is also needed is a catheter with injectors which will not drag across the artery walls when the catheter is inserted or withdrawn from a patient.
A catheter in accordance with an embodiment of the invention comprises an injection port at or near the distal end thereof and a mechanism for directing the injection port angularly away from the central axis of the catheter and into the artery wall. (An injection port is a structure used for introducing medication or other material into a patient. The injection port typically is a hollow needle.) In one embodiment, the catheter includes a guide wire lumen for receiving a guide wire that enables a physician to direct the catheter to a desired location within the patient""s vascular system. Also, in one embodiment, the catheter includes a plurality of needles, each of which may be manipulated at an angle outwardly from the central longitudinal axis of the catheter so that the needles can inject a drug or medication into the surrounding tissue. Prior to deployment of the needles, the needles are retained such that they lie substantially parallel to the longitudinal axis of the catheter.
In one embodiment, a balloon is provided towards the distal end of the catheter for pushing the needles outwardly into the artery wall. In another embodiment, other mechanical means are provided for pushing the needles outwardly.
These and other features of the invention are described below.